How to change day wheels on a NH36A for a 4 O'Clock Case

When supercharging your SKX007 from a 7s26 to an NH36A, you'll notice that that day wheel is not correctly aligned. The reason for this is that the NH36A movements on the market have a 3 o'clock position and installing it onto a SKX007/Seiko Sport SRPD or a 4 o'clock case such as our NMK901 SKX007/SRPD Watch Case results in a misaligned day wheel.

The usual fix is to procure a day wheel from the 7s26, which has a 4 o'clock position. We now supply 4 o'clock replacement day wheels in Kanji that you can simply install on the Seiko NH36A - this is also perfect for full builds from the ground up using a 4 o'clock case.

Are you ready? Let's go!

Tools you'll need:

1. Hands lever

2. Rodico

3. Tweezers

Step One:

Gently pry off the C-clip from the movement with the hands lever, going around slowly to loosen it first.

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Step Two: 

Once the C-clip has been removed, put it aside (do not lose it, it's tiny!) and use a little blob of Rodico to lift out the stock day wheel. A tweezer works fine too but be careful not to scratch anything.

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Step Three:

Fit the replacement day wheel into position with a bit of Rodico and a tweezer to adjust the final placement. You can also rotate the movement holder while pressing down on the day wheel to ensure it is set in place and that the day wheel is seated perfectly flush with the date wheel.

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Step Four:

Time to reinstall the C-clip! Gently fit it back into the original position.

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Step Five:

Almost there! You'll want to snap the C-clip back into position. We find that using two hands levers is the easiest way to get this done but the tips of the tweezers will do the job too.

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Step Six: 

Wind the time (last position) on the movement to allow the date and day wheels to naturally turn once it goes past midnight. A full revolution should do the trick if you're not sure where the movement is at.

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That's it, you're done champ. Easy peasy! You should be able to freely change the day wheel now. Happy modding modfam!

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For a more in-depth and detailed explanation, our good friend Darak (of Darak Watches) also made a great video about this here: https://youtu.be/kAccb7cOY6s